Over the years, many significant improvements have been made in the design and operation of fuel injection apparatuses for both spark and compression ignition engines. Today, fuel injection nozzles are compact and simple devices having a high degree of efficiency. One of the problems which has been encountered by engineers in incorporating these improved injection devices within internal combustion engines has been the detrimental effect of high temperature cylinder gases acting upon the outlet end of the nozzle. These gases can enter the annular space formed between the nozzle and the surrounding bore and cause heating and carbonization problems.
In order to prevent the bypass of cylinder gases through the annular space between the nozzle and the surrounding bore formed in the cylinder head, engineers have utilized annular seals or gaskets of conventional designs which are sometimes disposed within annular recesses formed circumferentially about the tubular nozzle. One drawback of these seals is that they are not compressible as the fuel injection nozzle is axially aligned within the stepped bore. A second drawback can occur should a height differential exist between the shoulder of the fuel injection nozzle and the step of the stepped bore. This dimensional difference reduces the effectiveness of the seal and permits the passage of combustion gas to the upper portion of the fuel injection nozzle.
Now a seal has been designed which will account for minor dimensional differences which may exist between the shoulder of the fuel injection nozzle and the step of the stepped bore.